Scientific Forecaster Discussion

Synopsis... low pressure will move through the central Great Lakes overnight and reach Quebec on Monday. A trailing cold front will drop across the area early Monday. A second cold front will follow on Tuesday. Tuesday evening and Wednesday high pressure will build back into the Ohio Valley.

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Near term /until 6 am Monday morning/... cap still keeping convection from firing over or near the County Warning Area. Late this evening... models show a strong short wave dropping southeast into the area which will also serve to increase moisture and synoptic lift supporting elevated convection. While the strongest convection appears to continue mainly east...models show a weakening line of showers and thunderstorms dropping southeast across the area mainly after 05z eventually affecting most of the area by morning. Best chance to remain dry will be the southeast counties. Mav guidance temperatures look fine in the middle 60s to near 70 for one more night in the warm sector.

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Short term /6 am Monday morning through Wednesday night/... cold front should be across northwestern Ohio by 12z with showers and possibly a few thunderstorms ongoing across the eastern and southern counties. While the western counties dry through the late morning and afternoon the nam12 continues to show sufficient moisture for at least chance probability of precipitation into the afternoon. Also a fairly strong short wave will be rotating through the base of the trough which will be just to our north. In all...will only slowly decrease probability of precipitation east through the day. Monday night the NAM and GFS both show drying moving in from the west although deep moisture associated with the upper low over the Great Lakes will be just to our north. The NAM is drier than the GFS here but will side more toward the NAM and go with a dry forecast most areas. Will keep a low chance pop northwestern PA and far northestern Ohio as the wrap around moisture should catch that area first. Tuesday another short wave rotating through the base of the upper low will likely allow some of this wrap around moisture to drop into at least the northestern portion of the area. Will bring clouds into the NE for the day along with chance probability of precipitation. Continued dry and pc remainder of the area. Wednesday the upper low tries to shift east. Models differ of the character of the day however as the NAM shows a dry slot across the area with subsidence and a surface high. The GFS is more progressive quickly moving the dry air east and moving in a short wave and deep moisture out of the Midwest. The European model (ecmwf) has this feature as well however it remains further west. For now will only bring a low chance pop to the far southwest during the afternoon and continue dry elsewhere. Will expand the chance probability of precipitation a bit Wednesday night.

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Long term /Thursday through Sunday/... the ridge across the western U.S. And the trough across the east will continue through the weekend. This will keep temperatures running below normal for early August...low/mid 70s only. Shortwave energy will be moving out of the plains and to the lower Ohio Valley. A surface low will track along the Ohio Valley Thursday and to the East Coast by Friday. Canadian high pressure will settle more firmly across the lower Great Lakes for the weekend. There will be timing and track adjustments that will need to be made with this system.

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Aviation /00z Monday through Friday/... a line of storms from eastern WI across lower Michigan continues to move east-southeast toward the local area. Timing of this precipitation puts it over ktol around 04z and to kcle between 06 and 07z. These two sites are the only ones that have a legitimate shot for thunder as the line is expected to weaken after sunset. Expect the precipitation to make it to kmfd and kcak before breaking up. Only small chances for precipitation exist at kyng and Keri overnight. The surface cold front will move through Monday morning. It is possible some redevelopment could occur during the afternoon and have given kcak and kyng a small mention. Expect the other taf sites to be dry. Gusty S to SW flow will continue overnight. Peak gusts should drop to around 20 knots after sunset. Expect the flow to become westerly behind the surface front. Some patches of MVFR ceilings are possible behind the front. Do not think this condition will persist very long.

Outlook...there will be a few opportunities for non VFR weather Wednesday through Friday.

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Marine... it will be a rather breezy period on the lake from this evening through Tuesday. A cold front will cross the lake early Monday morning. Ahead of it a couple rounds of showers/thunderstorms possible. Some thunderstorms may make it into the western basin by 6pm and they may be on the strong side. Otherwise the bulk of the storms will arrive overnight. Southwest winds will increase this evening to 25 knots...shifting to the west on Monday morning and early afternoon and decreasing some. Have extended the Small Craft Advisory eastward starting later this evening. Winds will back to the southwest as a secondary trough approaches for Tuesday. Winds will peak at 10 to 20 knots with this trough. Finally by Wednesday high pressure will be building across the region and wind/waves will calm down. For the second half of the week winds will come around to the northeast as low pressure tracks across the Ohio Valley to the virginias to end the work week.